An imager making use of an electrophotographic imaging process comprises developer equipment for developing latent images on a photosensitive drum. For this developer, as shown typically in FIG. 12, there is a developer 61 known so far in the art, which is of the structure that comprises a hopper 62, a developing roller 63, a rotatable agitator 64 and a developing blade 65 (JP(A)2003-43812). With this developer 61, a toner 66 in the hopper 62 is fed by the agitator 64 to the developing roller 63 so that the toner in thin layer form is uniformly carried on the peripheral surface of the developing roller 63 by frictional electrification between the developing blade 65 and the developing roller 63. And then, the toner 66 passes from the developing roller 63 onto the photosensitive drum 67 with a latent image formed on it for development.
As shown typically in FIG. 13, the developing blade 65 known so far in the art is of the structure that comprises a rubber blade member 74 along the side edge 72A of a metallic support member 72 having a thickness of about 0.1 mm.
A problem with the conventional developing blade is, however, that the support member 72 is deformed and warped toward the blade member 74 depending on differences in thermal shrinkage between them, because the blade member 74 is formed on one surface of the support member 72. The developing blade undergoing such warpage is poor in handling capabilities, and poor in mounting capabilities as well, because the deformed product must be flattened for mounting.
And now, the aforesaid warping of the developing blade may be held back by increasing the thickness or width of the support member 72 or diminishing the width of the blade member 74. However, as the thickness or width of the support member 72 grows large, it causes the spring action of the support member 72 to become worse, often doing some detriment to the appearance of the function of the developing blade in the developer or working to the detriment of size reductions of the developer, resulting in added manufacturing costs. A problem with diminishing the width of the blade member 74 is that it is difficult to form the blade member 74 by means of molding or it is detrimental to the appearance of the function of the developing blade in the developer.